Apical extrusion of in different canal geometries during the use of nickel titanium systems with different motion types.

BACKGROUND/PURPOSE: Extrusion of intracanal bacteria leads to treatment failures. Compare the apical extrusion of intracanal bacteria () during canal preparation with three different instrumentation techniques [RECIPROC, One Shape (OS), and Twisted-File Adaptive (TFA)] with different motion types.

MATERIALS AND METHODS

Ninety teeth with different canal morphologies were divided into three main groups, each including 30 teeth (10 mandibular incisors, 10 mandibular premolars, and 10 curved roots). Roots were resected until 13-mm working length was obtained and fixed to glass vials filled with brain-heart infusion broth. Each canal was filled with suspension. The three main groups were further grouped into three subgroups. Each group was further subgrouped into three, with each subgroup including 10 roots from each type of teeth (10 incisors/subgroup, 10 premolars/subgroup, and 10 curved canals/subgroup). These subgroups were prepared with one of RECIPROC, OS, or TFA. Bacterial colonies extruded into each vial were incubated in brain-heart infusion agar at 37°C for 5 days and counted using a colony counter as the number of colony-forming units per milliliter. Statistical analyses were performed using one-way analysis of variance, Tukey honest significant difference, and Kruskal-Wallis tests.

RESULTS

Apically extruded bacteria were not statistically different from each other (P > 0.05). The amount of apically extruded bacteria was statistically similar for both different instruments in the same type of tooth (P > 0.05) and same instrument in different types of teeth (P > 0.05).

CONCLUSION

Neither the motion type of instrument nor the canal morphology affected the degree of bacterial extrusion.